The invention relates generally to the field of controllers for check-responsive operation of mechanical vending equipment. More particularly, the invention pertains to escrow controllers for vending machines such as copiers or the like having a mechanical vend path.
An "escrow controller" is a controller for vending which has the capability of accumulating (escrowing) value deposited by a customer until a given value is deposited, at which time the machine which is controlled is allowed to dispense whatever product or service is applicable.
Many prior art escrow controllers physically "escrowed" (that is, held) the coins deposited until a vend signal or coin return signal was received, then dumped the escrowed coins into the cash box or coin return slot.
Most, if not all, prior art escrow controllers were of the "escrow to vend" type. That is, the value deposited is escrowed until the vend price is deposited. Then the vending machine is enabled, and (sometimes after waiting to receive a vend signal from the machine) the coins are dumped into the coin box or changer tubes and (as appropriate) change is returned. Many escrow-to-vend controllers have been patented, such as Arseneau, U.S. Pat. No. 3,815,717 [1974]; several Levasseur patents including 3,841,456 [1974], 4,008,792 [1977], 4,359,147 [1982], and others.
This method of operation is satisfactory in situations, such as soda or candy venders, where typically a single vend is performed for each customer (i.e. one only wants a single can of soda) and the vend is essentially instantaneous (once the machine is enabled, the can is dispensed, and the vend is over).
Such controllers are less desireable in such applications as coin-operated photocopiers. Usually, a user of a copier will want to make more than one copy. He may want to add additional value during the copying process. The copying process is not instantaneous--the paper path may be several feet long from feed bin to finished copy. Thus, it becomes necessary to hold the vend enable signal on, sense when a copy is has been made by waiting for a signal from the copier, deduct the cost of a copy from the escrow amount, and (if the escrow value has been used up) turn off the vend enable.
The copy machine can provide a pulse indicating that the copy has reached a certain point in its path, but this pulse can be derived from the feed rollers ("early"), or at some point at exposure or drum contact ("mid-path"), or at the point where the copy is ejected from the machine ("late").
An earlier patent of the present inventor, Rademacher, et. al., U.S. Pat. No. 4,519,088 [3/21/85], entitled "Usage Control System", and assigned to the assignee hereof, addressed the problem of dealing with copiers having an early or mid-path copy sense (reset) pulse. Such a copier requires an additional delay before turning off the vend enable, lest the copy be "caught" in the copy path. That patent, however, was primarily concerned with a single copy coin system, or a card-operated system, where the concern was not to catch the copy in the copy path.
In an escrow control situation with machines having mid-path or late count pulses, another problem surfaces, in addition to the problem described in the early pulse problem. If the escrow amount is debited when the count pulse is received, and the vend enable is turned off when the escrow value reaches zero (or less than one vend price), then there may be one or more copies which have already been made in the copy path, for which there is no value escrowed. The user can then get one or more free copies, if the delay of the Rademacher, et. al., patent is implemented (or if the copier allows the cycle to complete despite the lack of the enable signal). Alternatively, in some machines, without the delay the later copies may be "trapped" in the copy path and jam the machine.
Escrow controllers can be prone to another problem, as well. If a bill acceptor is part of the system, a user may insert a bill, be credited with the value of the bill, then activate the coin return. The controller will return the value of the bill in coins, and thus can be used as a bill-changer. This is especially troublesome in applications such as school libraries or the like, where the change-maker on the copier can be quickly depleted so as to provide change for the soda machine.
It is thus an object of the invention to provide an escrow credit controller suitable for use with copier machines which allows a customer to enter value for multiple vends (copies).
It is a further object of the invention to provide an escrow credit controller suitable for use with copier machines which allows a customer to enter value during the copying process, regardless of the status of the escrow value or of the vending machine.
It is a further object of the invention to provide an escrow credit controller suitable for use with copier machines which allows a customer to make multiple copies, the cost of which is debited against the escrow value.
It is still another object of the invention to provide an escrow credit controller suitable for use with copier machines which will not permit a customer to receive free copies when the escrow value is depleted.
It is also an object of the invention to provide an escrow credit controller suitable for use with copier machines which can, in an alternate embodiment, prevent its use as a bill changer.